PHP Challenges: Compute the sum of the two reversed numbers and display the sum in reversed form

PHP Challenges - 1: Exercise-17 with Solution

Write a PHP program to compute the sum of the two reversed numbers and display the sum in reversed form.

Input : 13, 14

Note : The result will not be unique for every number for example 31 is a reversed form of several numbers of 13, 130, 1300 etc. Therefore all the leading zeros will be omitted.

Explanation :

Sample Solution :

PHP Code :

<?php
// Function to find the reverse sum of two numbers
function reverse_sum($n1, $n2)
{
    // Return the sum of the reverse of both numbers
    return reverse_integer($n1) + reverse_integer($n2);
}

// Function to reverse an integer
function reverse_integer($n)
{
    // Initialize variable to store the reversed integer
    $reverse = 0;
    
    // Loop until the input number becomes 0
    while ($n > 0)
    {
        // Multiply the current reversed number by 10 and add the last digit of the input number
        $reverse = $reverse * 10;
        $reverse = $reverse + $n % 10;
        
        // Remove the last digit from the input number
        $n = (int)($n / 10);
    }
    
    // Return the reversed integer
    return $reverse;
}   

// Test the reverse_sum function with different inputs and print the results
print_r(reverse_sum(13, 14) . "\n");
print_r(reverse_sum(130, 1) . "\n");
print_r(reverse_sum(305, 794) . "\n");
?>

Explanation:

Here is a brief explanation of the above PHP code:

• Function definition:
• The code defines a function named "is_geometric()" which checks if an array forms a geometric sequence. It takes an array '$arr' as input.
• Inside the function:
• It first checks if the array size is 1 or less. If so, it returns 'True' as any sequence with 1 or fewer elements is considered geometric.
• It calculates the ratio between the second and first elements of the array.
• It iterates through the array elements starting from the second element.
• Within each iteration, it checks if the ratio of the current element to the previous element is equal to the initial ratio calculated.
• If any ratio is not equal to the initial ratio, it returns "Not a geometric sequence".
• If all ratios are equal, it returns "Geometric sequence".
• Function Call & Testing:
• Two arrays '$my_arr1' and '$my_arr2' are defined with different sets of numbers.
• The "is_geometric()" function is called twice with these arrays as input.
• Finally, "print_r()" function displays whether each input array forms a geometric sequence.

Sample Output:

72                                                          
32                                                          
1000 

Flowchart:

PHP Code Editor:

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